Fusion of male and female sex cells (gametes) produced by the same individual.
This type of fertilization occurs in bisexual organisms, including most flowering plants, numerous protozoans, and many invertebrates. Many organisms capable of self-fertilization can also reproduce by means of cross-fertilization . As an evolutionary mechanism, self-fertilization allows an isolated individual to create a local population and stabilizes desirable genetic strains, but it fails to provide a significant degree of variability within a population and thereby limits the possibilities for adaptation to environmental change.